Bug 1109954 - Make resolve/reject values optional in callback signatures. r=cpearce

dom/media/MediaDecoderStateMachine.cpp

@@ -2491,10 +2491,9 @@ MediaDecoderStateMachine::ShutdownReader()
 }
 
 void
-MediaDecoderStateMachine::FinishShutdown(bool aSuccess)
+MediaDecoderStateMachine::FinishShutdown()
 {
   MOZ_ASSERT(OnStateMachineThread());
-  MOZ_ASSERT(aSuccess);
   ReentrantMonitorAutoEnter mon(mDecoder->GetReentrantMonitor());
 
   // The reader's listeners hold references to the state machine,

dom/media/MediaDecoderStateMachine.h

@@ -163,7 +163,7 @@ public:
   void SetDormant(bool aDormant);
   void Shutdown();
   void ShutdownReader();
-  void FinishShutdown(bool aSuccess);
+  void FinishShutdown();
 
   // Called from the main thread to get the duration. The decoder monitor
   // must be obtained before calling this. It is in units of microseconds.

dom/media/MediaPromise.h

@@ -155,6 +155,32 @@ protected:
     const char* mCallSite;
   };
 
+  /*
+   * We create two overloads for invoking Resolve/Reject Methods so as to
+   * make the resolve/reject value argument "optional".
+   */
+
+  // Avoid confusing the compiler when the callback accepts T* but the ValueType
+  // is nsRefPtr<T>. See bug 1109954 comment 6.
+  template <typename T>
+  struct NonDeduced
+  {
+    typedef T type;
+  };
+
+  template<typename ThisType, typename ValueType>
+  static void InvokeCallbackMethod(ThisType* aThisVal, void(ThisType::*aMethod)(ValueType),
+                                   typename NonDeduced<ValueType>::type aValue)
+  {
+      ((*aThisVal).*aMethod)(aValue);
+  }
+
+  template<typename ThisType, typename ValueType>
+  static void InvokeCallbackMethod(ThisType* aThisVal, void(ThisType::*aMethod)(), ValueType aValue)
+  {
+      ((*aThisVal).*aMethod)();
+  }
+
   template<typename TargetType, typename ThisType,
            typename ResolveMethodType, typename RejectMethodType>
   class ThenValue : public ThenValueBase
@@ -187,12 +213,12 @@ protected:
   protected:
     virtual void DoResolve(ResolveValueType aResolveValue)
     {
-      ((*mThisVal).*mResolveMethod)(aResolveValue);
+      InvokeCallbackMethod(mThisVal.get(), mResolveMethod, aResolveValue);
     }
 
     virtual void DoReject(RejectValueType aRejectValue)
     {
-      ((*mThisVal).*mRejectMethod)(aRejectValue);
+      InvokeCallbackMethod(mThisVal.get(), mRejectMethod, aRejectValue);
     }
 
     virtual ~ThenValue() {}

dom/media/mediasource/MediaSourceReader.cpp

@@ -299,14 +299,13 @@ MediaSourceReader::Shutdown()
   MOZ_ASSERT(mMediaSourceShutdownPromise.IsEmpty());
   nsRefPtr<ShutdownPromise> p = mMediaSourceShutdownPromise.Ensure(__func__);
 
-  ContinueShutdown(true);
+  ContinueShutdown();
   return p;
 }
 
 void
-MediaSourceReader::ContinueShutdown(bool aSuccess)
+MediaSourceReader::ContinueShutdown()
 {
-  MOZ_ASSERT(aSuccess);
   if (mTrackBuffers.Length()) {
     mTrackBuffers[0]->Shutdown()->Then(GetTaskQueue(), __func__, this,
                                        &MediaSourceReader::ContinueShutdown,

dom/media/mediasource/MediaSourceReader.h

@@ -180,7 +180,7 @@ private:
 
   bool mHasEssentialTrackBuffers;
 
-  void ContinueShutdown(bool aSuccess);
+  void ContinueShutdown();
   MediaPromiseHolder<ShutdownPromise> mMediaSourceShutdownPromise;
 #ifdef MOZ_FMP4
   nsRefPtr<SharedDecoderManager> mSharedDecoderManager;

dom/media/mediasource/TrackBuffer.cpp

@@ -112,9 +112,8 @@ TrackBuffer::Shutdown()
 }
 
 void
-TrackBuffer::ContinueShutdown(bool aSuccess)
+TrackBuffer::ContinueShutdown()
 {
-  MOZ_ASSERT(aSuccess);
   ReentrantMonitorAutoEnter mon(mParentDecoder->GetReentrantMonitor());
   if (mDecoders.Length()) {
     mDecoders[0]->GetReader()->Shutdown()

dom/media/mediasource/TrackBuffer.h

@@ -160,7 +160,7 @@ private:
   // Protected by mParentDecoder's monitor.
   MediaInfo mInfo;
 
-  void ContinueShutdown(bool aSuccess);
+  void ContinueShutdown();
   MediaPromiseHolder<ShutdownPromise> mShutdownPromise;
 };